Well Early Access only has the first 4 levels worth of spells.
About 6-8 skills per tree...
I honestly have no idea. It is very possible there are LESS spells as there will likely be a nuke taken to the Summons, shields, and avatars.
Then there are skills that have been folded into each other.
-First Aid is combined with Doctor and Cure Poison.
-Fortitude is likewise combined with a few other skills
I THINK this game will have more, I know they shown us ALL the skill icons, so we could count those.